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XOOPS is a program more than a programming language. It is written in PHP (~programming language) and is presented in HTML (like almost everything on the Internet)
I have absolutely no idea, what you want to drag and drop where.
The difference is not in the displaying of sites, but in the managing of sites. Instead of having to make each and every page by hand in HTML, you can make a generic page layout and let the items being displayed depend on information in a database.
XOOPS gives a way to add specific pages (modules) to do specific things (like a message board, display news, show a calendar etc.)
If what you mean is the theming (the "skin" of the site with colours and generic graphics) then you should look at the various themes available. It is one page (theme.html) deciding the placement of blocks, header image and similar and which loads a style sheet (style.css) to decide background colours etc.
Apart from some Smarty code (a mix between programmable logic and plain HTML) the theme.html file is a plain HTML file, which you can load into dreamweaver and work with there.